30A O.C.P. FOR LIGHTING

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sam34

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Is there at any condition a 30A breaker can be used to power a lighting loads (for any voltage system, 480v or 208v). I have a situation where
a 1000W are used for parking lot. (trying to get more lights on one circuit). Thank you
 
Re: 30A O.C.P. FOR LIGHTING

Yes, you can use 30A branch circuits for fixed lighting units with heavy duty lampholders in other than dwelling units (210.23B). You can also use 40 and 50 amp circuits (210.23C).

Steve
 
Re: 30A O.C.P. FOR LIGHTING

I beleive NEC 200 Art 210.21(A) and Art 210.23(B) might cover this.
 
Re: 30A O.C.P. FOR LIGHTING

sam34, For this application I would run the 30 40 or 50 amp feeder from pole to pole and specify inline fuseholders (something like Bussman Type KK fuses) and tap from the feeder at the pole handhole. 1000W heads in a parking area is probably 2, 3, or 4 heads per pole and there should be ample space to have the fuseholders installed at the handhole access. Each luminaire would tap from the main feeder (which could be #8 #6 or #4 depending upon load and VD factors) and the wiring that runs from the tap to the luminaire could be #12.
For additional capacity of the circuit the feeder that runs to each pole could be a 3 phase feeder, and the 480 or 208 volt luminaires could tap from the phase legs A-B, A-C, B-C etc to ensure balanced loading. This will enable additional capacity with each circuit at the cost of pulling another phase leg.

Lets assume 480 volt, 30a 3 phase circuit.
30 x .8 = max continuos load of 24 amps.
24 x 830 = 19920 max va
19920 / 1250W (1000W head w/ ballast load) = 15.936
Therefore 15 heads (balanced on the 3 phases of course) on a 30a-3ph circuit would be the maximum.

Consider that against a 480 volt 20a-1ph circuit, which could carry a maximum of 6 luminaires.
 
Re: 30A O.C.P. FOR LIGHTING

Good point marketman. If you add fuses at each pole, the circuits running to the poles are now feeders, and not subject to the branch circuit limitations. (Although I doubt there would be any advantage to using a feeder larger than 50A.)

Steve
 
Re: 30A O.C.P. FOR LIGHTING

Thank you all for your respond, I'll take that route which I'll be adding fuseholders (20A) at each pole handhole and tap from there.Also, I'll be feeding it from 30A/3p breaker.
 
Re: 30A O.C.P. FOR LIGHTING

Steve,
If you add fuses at each pole, the circuits running to the poles are now feeders, and not subject to the branch circuit limitations.
Click to expand...
I don't agree. The fuses at each pole are supplementary overcurrent protection. The supply is still a branch circuit, not a feeder.
Don
 
Re: 30A O.C.P. FOR LIGHTING

Originally posted by don_resqcapt19:
Steve,
If you add fuses at each pole, the circuits running to the poles are now feeders, and not subject to the branch circuit limitations.
Click to expand...
I don't agree. The fuses at each pole are supplementary overcurrent protection. The supply is still a branch circuit, not a feeder.
Don
Click to expand...
Don how did you arrive at this conclusion given the article 100 definitions?

Not really arguing with you just confused.

If I run a 100 amp circuit out to a series of 30 amp disconnects that circuit would be a feeder.

How are these fuses different?

It seems it is up to the installer to decide if these fuses are branch circuit protection or supplementary overcurrent protection.

Confused, Bob
 
Re: 30A O.C.P. FOR LIGHTING

Originally posted by sam34:
Thank you all for your respond, I'll take that route which I'll be adding fuseholders (20A) at each pole handhole and tap from there.Also, I'll be feeding it from 30A/3p breaker.
Click to expand...
I've done this job a few times in the past. The fuses we generally use are rated much lower than the 20A, you suggest. We try and keep the fuse size inline with the actual draw of the heads. The idea is, if a head should malfunction that particular fuse will blow. If multiple heads should fail, only fuses blow and NOT the OCP.
The 20A fuse suggestion *could* allow for an excessive amount of amp to be drawn on the feeder and blow the OCP ~ result: the whole lot is dark.
An example of this excessive draw would be mismatched ballasts and bulbs.
 
Re: 30A O.C.P. FOR LIGHTING

sam34,

If your OCPD is 30a3p c.b. then you may just run #10 from handhole to fixture,although adding fuse protection is a better job.

frank
 
Re: 30A O.C.P. FOR LIGHTING

Bob,
I guess it depends on what fuse is used at the pole. Many of the smaller fuses are not listed for use as branch circuit protection.
Look at these fuses. Many times these are the types of fuses used in poles or other light fixtures. There are also small breakers like those commonly used in control panels that are not listed as suitable for use as branch circuit protection.
Don
 
Re: 30A O.C.P. FOR LIGHTING

This type of fuse is also often used and the fuse listed only for supplemental protection, and the holder is not listed for field installation. UL Guide IZLT2 says:
The devices covered under this category are incomplete in certain constructional features or restricted in performance capabilities and are intended for use as components of complete equipment submitted for investigation rather than for direct separate installation in the field. THE FINAL ACCEPTANCE OF THE COMPONENT IS DEPENDENT UPON ITS INSTALLATION AND USE IN COMPLETE EQUIPMENT SUBMITTED TO UNDERWRITERS LABORATORIES INC.
Click to expand...
Don
 
Re: 30A O.C.P. FOR LIGHTING

Don Thanks for those posts, that makes sense.

So I have to pay attention to what the OCPD itself is listed for in order to determine if it can be a branch circuit or supplementary OCP.

Sorry I was slow to get back to this one.

Bob
 
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